Author(s)

Examples

## Define the universe
uni <-list(asia =c("yes","no"), tub =c("yes","no"), smoke =c("yes","no"),
lung =c("yes","no"), bronc =c("yes","no"), either =c("yes","no"),
xray =c("yes","no"), dysp =c("yes","no"))
e1 <-list(dysp="no", xray="no")
eo1 <-new_ev( e1,levels=uni )
eo1
as.data.frame( eo1 )
eo1 %>%str
e1.2 <-list(dysp="no", xray=c(0,1))
eo1.2 <-new_ev( e1.2,levels=uni )
eo1.2
# Notice that in \code{eo1.2}, \code{xray} is not regarded as hard# evidence but as a weight on each level. Other than that \code{eo1.2}# and \code{eo1} are equivalent here. This is used in connection# with specifying likelihood evidence.
e2 <-list(dysp="yes", asia="yes")
eo2 <-new_ev(e2, uni)# If evidence 'e1' is already set in the network and new evidence# 'e2' emerges, the evidence in the network must be updated. But# there is a conflict in that \code{dysp="yes"} in 'e1' and# \code{dysp="no"} in 'e2'. The (arbitrary) convention is that# existsting evidence overrides new evidence so that the only new# evidence in 'e2' is really \code{asia="yes"}.# To subtract existing evidence from new evidence we can do:setdiff_ev( eo2, eo1 )# Likewise the 'union' isunion_ev( eo2, eo1 )